[DCCP] CCID2: Initial CCID2 (TCP-Like) implementation

Original work by Andrea Bittau, Arnaldo Melo cleaned up and fixed several
issues on the merge process.

For now CCID2 was turned the default for all SOCK_DCCP connections, but this
will be remedied soon with the merge of the feature negotiation code.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 2ab6f0e..38321ad 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -1081,6 +1081,7 @@
 	dp->dccps_mss_cache = 536;
 	dp->dccps_role = DCCP_ROLE_UNDEFINED;
 	dp->dccps_service = DCCP_SERVICE_INVALID_VALUE;
+	dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
 
 	return 0;
 }